Field of the Invention
The present invention relates to a rollable display.
Discussion of the Related Art
With the development of information technology, the market for displays, which act as an intermediary between users and information, is growing. Thus, the use of display devices such as organic light-emitting displays (OLEDs), liquid crystal displays (LCDs), and plasma display panels (PDPs) is increasing.
Among them, the organic light-emitting diode displays are self-emissive, and hence may have lower power consumption and thinner profile than the liquid crystal displays, which require a backlight. Also, the organic light-emitting diode displays offer advantages like wide viewing angle and fast response time. The processing techniques for organic light-emitting diode displays have been developed to an extent that allows mass production of large screens, and the organic light-emitting diode displays are expanding the market share, competing with the liquid crystal displays.
Pixels of an organic light-emitting diode display comprise organic light-emitting diodes (hereinafter, “OLEDs”), which are self-emissive. The organic light-emitting diode display may be classified as a variety of displays, depending on the type of emissive material, the emission method, the emission structure, and the driving method. The organic light-emitting diode displays may be classified as fluorescent emission devices or phosphorescent emission devices depending on the emission method, or classified as top emission devices or bottom emission devices depending on the emission structure. Also, the organic light-emitting diode displays may be classified into Passive Matrix OLEDs (PMOLEDs) and Active Matrix OLEDs (AMOLEDs).
Flexible displays have recently become commercially available. A flexible display can reproduce input images on the screen of a display panel where plastic OLEDs are formed. The plastic OLEDs are formed on a bendable plastic substrate. The flexible displays can come in various designs and offer benefits in portability and durability. The flexible displays may be implemented in various ways such as a bendable display, a foldable display, a rollable display, etc. Such flexible displays can be used in TVs (televisions), car displays, and wearable devices, as well as mobile devices such as smartphones and tablet PCs, and are broadening their range of applications.
A rollable display's display panel can be rolled up or unrolled as needed. The display panel may be made relatively thin and have a low self-weight so that it can be easily rolled up or unrolled and provides better aesthetic appearance in terms of design. However, a thin and lightweight display panel provides low physical durability. Thus, the display panel may be easily damaged by an external force applied to it, and this lowers the product's reliability and stability. Accordingly, there is a need for a solution to this problem.